The Password for the electro barrier in the Plasma ship post Shizui is the opposite of the two shown legendaries name in Japanese to the version you are playing, so White 2 would be Zekrom and Reshiram for Black 2.

The Password for the electro barrier in the Plasma ship post Shizui is the opposite of the two shown legendaries name in Japanese to the version you are playing, so White 2 would be Zekrom and Reshiram for Black 2.